Self-oiling die stock



oa. 14, 195s C. B. SIMON SELFr-OILING DIE STOCK Filed Dec. 24, 1957 1 30 O i 7 O0 1 j 2 j 2 i j 1... Jv" I4 A l! Y ...un M 1 3.. m y l# if. 1NM- SELF-OILING DIE STCK Clarence B. Simon, Little Rock, Ark.Application December 24, 1957, Serial No. 705,027

6 claims. (ci. 11i- 126) This invention relates to a die stock for usein threading 'bolts and studs, and particularly to the provision or adie stock so constructed as to automatically supply a constant llow oflubricating oil to the cutting die and the work piece during thethreading operation.

ln order to prolong the life of the cutting die, and also in order toobtain perfect threads, it is essential that both the die and the boltor stud being threaded be supplied with a quantity of oil suticient tolubricate the cutting teeth of the die, cool both the die and the workpiece, and aid in the removal of the metallic chips produced by thethreading operation. While it is generally recognized that it would bepreferable to have the lubricating oil supplied at a fairly constantrate throughout the thread-cutting operation, it is obvious that thiscannot be done with a conventional die stock, which requires that theoperator use both hands to turn it and, thus, makes it impossible forhim to apply lubricating oil while the die stock is being operated.

The requirement that the operator interrupt the threadcutting operatic-neach time it becomes necessary to apply lubricating oil to the cuttingdie and the work piece is, perhaps, the principal disadvantage of theconventional die stock. In actual practice, it has been found that,during these interruptions, the operator normally applies too much oilto the cutting die and work piece, but nevertheless nds that, by thetime he has wiped his hands and resumed the threading operation, thereis not enough oil remaining at the point where it is needed, the bulk ofit having run E or dripped onto nearby pieces of machinery andequipment, possibly damaging the same, or even onto the oor, therebycreating safety hazards.

A second major disadvantage of the conventional twohanded die stockarises out of the requirement that the operator shift the position ofhis hands with each 180 turn of the die stock. This constant shifting ofthe operators hands results in a large number of ileeting interruptionsof the threading operation which, when added to the time consumed by theinterruptions required for the purpose of lubricating the cutting dieand the work piece, substantially increase the length of time requiredto complete'each individual piece of Work.

Another disadvantage of the conventional die stock is that aws andinaccuracies in the finished threads sometimes result from the repeatedinterruptions and resumptions of the threading operation which must bemade to enable the operator to lubricate the cutting die, and also toshift the position of his hands to turn the die stock.

It is therefore, the primary purpose of the present invention to providea die stock having a self-contained reservoir from which lubricating oilis automatically supplied to the cutting die and work piece at arelatively constant rate while the threading operation is in progress,but without requiring any elort or regulatory action on the part of theoperator, thus enabling him to complete an entire thread-cuttingoperation without any interruption for lubricating purposes.

vUnited States Patent O Patented Oct. 14, 1958 A related purpose is toprovide a die stock having a reservoir from which the lubricating oilwill not drip, flow or leak when the die stock is not in operation.

Another object is the provision of a die stock which the operator is notrequired to turn with his hands, but which is adapted to be rotated by astandard mechanics wrench or drive ratchet, thus eliminating theinterruptions occasioned by the constant shifting of operators hands andmaking it possible to complete an entire threadcutting operation fromstart to finish without any interruptions whatever.

A further object is to provide a die stock which, by virtue of its sizeand compactness, is adapted to be used for threading bolts and studslocated in relatively inaccessible positions.

A final object is the provision of a die stock which accomplishes all ofthe foregoing objects, yet is simple in construction, easy to operate,and relatively inexpensive to manufacture.

These objects are realized by the die stock embodying my invention, apreferred embodiment of which is shown in the drawings, wherein:

Figure l is an elevational view of the die stock, in cross section;

Figure 2 is a bottom plan view showing the cutting die locked inposition in the die stock;

Figure 3 is a sectional view along line 3 3 of Figure l; and

Figure 4 is an elevational view of the die stock in operation, showing abolt partly threaded.

As shown in Figure l of the drawings, the preferred embodiment of myinvention consists of a cylindrical tubular body 10, provided with atapered head -portion 11 having a socket type opening 12 adapted to beengaged by a conventional drive ratchet or electric wrench. The internalface 13 of tapered head portion 11 provides a flat seating surface for arubber liller tube or oil seal ring 14.

Located in the base of tubular body 10 is a screw 15, adapted toengage aconventional thread-cutting die 16 and maintain it in locked position inthe base portion of tubular body 10. By disengaging screw 15, die 16may, of course, be removed and replaced.

Also removably positioned within tubular body 10 are a rigid diaphragm17 having a slot 18 centrally located therein, two porous rubber inserts19 and 20, the rubber in which may be any one of several well knownoilresisting types, and a coiled spring 21, positioned between inserts19 and 2li.

Before beginning the thread-cutting operation, rubber inserts 19 and 20are saturated with lubricating oil, supplied through the openings in theopposite ends of tubular body 10, after which diaphragm 17 and cuttingdie 16 are locked into position by tightening screw 15. A conventionalmechanics wrench or drive ratchet 22 is then inserted into the socketopening 12 of the tapered head portion 11 of tubular body 10, thecutting die 16 positioned on the bolt 23 to be threaded, and the diestock rotated by mechanics wrench or ratchet 22 until the threadingoperation is complete.

lt will be seen that, as the threaded portion of bolt Z3 emerges fromthe teeth of cutting die 16, it forces diaphragm 17 progressivelyinwardly against rubber insert 19, thereby compressing said insert andcausing a portion of the oil contained therein to be released andsupplied, through slot 18 and around the edges of diaphragm 17 to theteeth of cutting die 16 and the threads of bolt 23. The increasingpressure exerted by bolt 23 against rubber insert 19 also overcomes, tosome extent, the outward force exerted by coil spring 21, therebytending to compress it inwardly against rubber insert 20, which iscompressed in turn against oil seal ring 14, with the result that aquantity of the oil contained in insert Ztl is also released and addedto the supply of oil being ted through insert 19 and slot 18 indiaphragm 17 to cutting die 16 and work piece 23. The oil thus releasedfrom insert 2? is Vprevented from escaping through the opening 12 in thehead portion 11 of tubular body il@ by virtue of the seal effected bythe interaction of 'rubber ring 14 and wrench or ratchet 22.

It will Vbe apparent from the foregoing description that a relativelyconstant flow of oil is supplied to the cutting die 16 and work piece 23throughout the threading operation, and that this is attributable to thefact that a progressively increasing forceV is being exerted on porousrubber oil reservoirs 19 and 20 while the amount of oil contained insaid reservoirs is progressively decreasing. By utilizing thisinterrelationship between the increased force being exerted on theporous rubber reservoirs and the diminishing supply of lubricating oilcontained, so as to release the oil at a relatively constant rate, thedie stock herein described eliminates the disadvantages heretoforeencountered in manually supplying lubricating oil and relieves theoperator of any responsibility for attending to'that particular phase ofthe threading operation.

Applicants invention not only provides an eminently satisfactorysolution to the problem of automatically supplying a constant flow oflubricating oil to the thread-cutting die and work piece, but alsoresults in the elimination of any ilaws or inaccuracies caused byrepeated interruptions and resumptions of the threading operation, asubstantial reduction of the time required for the threading of anygiven work piece, and the complete elimination of the time formerlyrequired to be spent in cleaning the cutting die, die stock, work pieceand surrounding machinery and equipment of excess oil manually suppliedby the operator of a conventional die stock. t

Having thus described my invention, what l claim as new and desire toobtain by United States Letters Patent is:

l. A self-oiling die stock consisting of a cylinder having means forengaging and holding a thread-cutting die in locked position in its baseportion; means adapted to receive a tool for rotating said cylinder inits head portion; and automatic oiling means positioned within saidcylinder, comprising a porous resilient insert of an oil-resistingmaterial, and a rigid slotted diaphragm adapted to be forcedlongitudinally inward against said insert by the operation of said diestock.

2` A self-oiling die stock consisting of a cylinder having means forengaging and holding a thread-cutting die in locked position in its baseportion; means adapted to receive a tool for rotating. said cylinder inits head portion; and automatic oiling means positioned within saidcylinder, comprising a porous resilient insert of an oilresistingmaterial, interposed between spring means and a rigid slotted diaphragmadapted to be forced longitudinally inward against said insert by theoperation of said die stock.

3. A self-oiling die stock consisting of a cylinder having means forengaging and holding a thread-cutting die in locked position in its baseportion; means adapted to receive a tool for rotating said cylinder inits head portion; and automatic oiling means positioned within saidcylinder, comprisingra pair of porous resilient inserts ot anoil-resisting material, spring means interposed between said inserts,and a rigid slotted diaphragm adapted to be forced progressively inwardagainst one of said' inserts as the threading operation proceeds.

4. A self-oiling die stock consisting of a cylinder having means forengaging and holding a thread-cutting die in locked position in its baseportion; a tapered head portion provided with means adapted to receive atool for rotating said cylinder; and automatic oiling means positionedwithin said cylinder, comprising a plurality of porous resilient insertsof an oil-resisting material, and a rigid slotted diaphragm adapted tobe forced progressively inward against one of said inserts as thethreading operation proceeds.

5. A self-oiling die stock consisting of a cylinder having means forengaging and holding a thread-cutting die in locked position in its baseportion; a tapered head portion provided with means adapted to receive atool for rotating said cylinder; and automatic oiling means positionedWithin said cylinder, comprising a rigid diaphragm having a slottherein, adapted to be forced longitudinally inward within said cylinderduring a threading operation, a porous rubber insert abutting saiddiaphragm, and spring means interposed between said rubber insert andthe tapered head portion of said cylinder, whereby said insert iscompressed outwardly against said diaphragm during a threadingoperation.

6. A self-oiling die stock consisting of a cylinder having means forengaging and holding a thread-cutting die in locked position in its baseportion; a tapered head portion provided with means adapted to receive atool for rotating said cylinder; and automatic oiling means positionedwithin said cylinder, comprising a rigid diaphragm having a slottherein, adapted to be forced longitudinally inward within said cylinderduring a threading operation, a first porous rubber insert abutting saiddiaphragm, a second porous rubber insert disposed adjacent the headportion of said cylinder, and spring means interposed between said firstand second rubber inserts, whereby said first insert is compressedoutwardly against said diaphragm and said second insert is compressedoutwardly toward said head portion during a threading operation.

No references cited,

